On Mon, Mar 01, 2021 at 09:21:16AM -0700, Nathan Chancellor wrote:
> On Mon, Mar 01, 2021 at 10:58:07AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> >
> > The patch below does not apply to the 5.4-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@xxxxxxxxxxxxxxx>.
> >
> > thanks,
> >
> > greg k-h
> >
> > ------------------ original commit in Linus's tree ------------------
> >
> > From 76d7fff22be3e4185ee5f9da2eecbd8188e76b2c Mon Sep 17 00:00:00 2001
> > From: Nathan Chancellor <nathan@xxxxxxxxxx>
> > Date: Fri, 15 Jan 2021 12:26:22 -0700
> > Subject: [PATCH] MIPS: VDSO: Use CLANG_FLAGS instead of filtering out
> > '--target='
> >
> > Commit ee67855ecd9d ("MIPS: vdso: Allow clang's --target flag in VDSO
> > cflags") allowed the '--target=' flag from the main Makefile to filter
> > through to the vDSO. However, it did not bring any of the other clang
> > specific flags for controlling the integrated assembler and the GNU
> > tools locations (--prefix=, --gcc-toolchain=, and -no-integrated-as).
> > Without these, we will get a warning (visible with tinyconfig):
> >
> > arch/mips/vdso/elf.S:14:1: warning: DWARF2 only supports one section per
> > compilation unit
> > .pushsection .note.Linux, "a",@note ; .balign 4 ; .long 2f - 1f ; .long
> > 4484f - 3f ; .long 0 ; 1:.asciz "Linux" ; 2:.balign 4 ; 3:
> > ^
> > arch/mips/vdso/elf.S:34:2: warning: DWARF2 only supports one section per
> > compilation unit
> > .section .mips_abiflags, "a"
> > ^
> >
> > All of these flags are bundled up under CLANG_FLAGS in the main Makefile
> > and exported so that they can be added to Makefiles that set their own
> > CFLAGS. Use this value instead of filtering out '--target=' so there is
> > no warning and all of the tools are properly used.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: ee67855ecd9d ("MIPS: vdso: Allow clang's --target flag in VDSO cflags")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1256
> > Reported-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> > Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> >
> > diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
> > index 5810cc12bc1d..2131d3fd7333 100644
> > --- a/arch/mips/vdso/Makefile
> > +++ b/arch/mips/vdso/Makefile
> > @@ -16,16 +16,13 @@ ccflags-vdso := \
> > $(filter -march=%,$(KBUILD_CFLAGS)) \
> > $(filter -m%-float,$(KBUILD_CFLAGS)) \
> > $(filter -mno-loongson-%,$(KBUILD_CFLAGS)) \
> > + $(CLANG_FLAGS) \
> > -D__VDSO__
> >
> > ifndef CONFIG_64BIT
> > ccflags-vdso += -DBUILD_VDSO32
> > endif
> >
> > -ifdef CONFIG_CC_IS_CLANG
> > -ccflags-vdso += $(filter --target=%,$(KBUILD_CFLAGS))
> > -endif
> > -
> > #
> > # The -fno-jump-tables flag only prevents the compiler from generating
> > # jump tables but does not prevent the compiler from emitting absolute
> >
>
> Attached are the 4.19 and 5.4 backports.
Both now queued up, thanks.
greg k-h
